Vertical shaft fuel tank cap with charcoal canister

ABSTRACT

The vertical shaft fuel tank cap with charcoal canister includes a fuel tank inner cap and fuel tank outer cap. A hollow room with an upper opening is disposed in the center of the fuel tank inner cap. The fuel tank outer cap is disposed above the fuel tank inner cap. The ventilating cap is disposed in the hollow room and divides the hollow room into filling room and containing room. The air outlet leading the fuel vapor to the containing room is disposed on the bottom of the containing room. The air interstice leading fuel vapor from the containing room to the filling room is disposed between the outer walls of the ventilating cap and inter wall of the containing room. The fuel-absorption substrate is disposed in the filling room. The filtering performance of charcoal powder can be enhanced since it is exempted from long-time fuel soaking.

RELATED U.S. APPLICATIONS

Not applicable.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not applicable.

REFERENCE TO MICROFICHE APPENDIX

Not applicable.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a kind of vertical shaft fuel tank cap with charcoal canister.

2. Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 37 CFR 1.98.

In the current market, most fuel tank cap contains a containing room filled by charcoal powder. When the inner pressure of the fuel tank is higher than the outer pressure, to achieve internal-external pressure balance, the fuel vapor in the fuel tank passes through and get filtered by charcoal powder, then be discharged to the atmosphere, to achieve the goal of emission control, and less environment pollution. However not all fuel vapor can be absorbed by this way. When the inner temperature is too high, or there is too much vibration within the fuel tank, some liquid fuel enters the containing room, soaks the charcoal powder for long time, and then determines the filtering performance of the charcoal powder.

SUMMARY OF THE INVENTION

The present invention is to solve the current technology problem by providing a kind of vertical shaft fuel tank with charcoal canister.

The invention solves the above technology problem by the technical solution as follows: a kind of vertical shaft fuel tank with charcoal canister comprises fuel tank inner cap and fuel tank outer cap. The hollow room with an upper opening is disposed in the center of the said fuel inner cap. The said fuel tank outer cap covering the upper opening of the hollow room is disposed above the said fuel tank inner cap. The ventilating cap is disposed in the said hollow room and divides the said hollow room into filling room and containing room. The said filling room is disposed above the said containing room. The air outlet leading the fuel vapor to the said containing room is disposed on the bottom of the said containing room. The air interstice leading fuel vapor from the said containing room to the said filling room is disposed between the outer walls of the said ventilating cap and inter wall of the said containing room. The fuel-absorption substrate is disposed in the said filling room.

The present invention has the advantages that: when gasoline engine stops, the residuary fuel in the containing room and filling room, through funnel-shaped bottom of the containing room and a plurality of air outlet on the bottom of the containing room, is drained completely and quickly into the fuel tank under the negative pressure of the fuel tank, for better charcoal powder filtering performance, and less environment pollution.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a structural schematic view of the present invention.

FIG. 2 is the structural schematic view of the present invention with fuel-absorption substrate.

FIG. 3 is the structural schematic view of the bottom of the ventilating cap with a plurality of gap.

FIG. 4 is the structural schematic view of the bottom of the fuel inner cap with screw thread.

DETAILED DESCRIPTION OF THE DRAWINGS

The following descriptions of the embodiment and its accompanying figures of the present invention are intended to illustrate and not to limit this invention.

FIG. 1 and FIG. 2 show the vertical shaft fuel tank cap with charcoal canister, comprising fuel tank inner cap 1, and the fuel tank outer cap 2, and the hollow room 3 with an upper-opening is disposed in the center of fuel tank inner cap 1.

The fuel tank outer cap 2 covering the upper opening of hollow room 3 is disposed above and non-hermetically connected with the fuel tank inner cap 1, thus the filtered fuel vapor can be discharged easily. The inter wall of fuel tank outer cap 2 and the top of fuel tank inner cap 1 are clamping connected.

The ventilating cap 4 is disposed in the hollow room 3 and divides the hollow room 3 into the filling room 31 and containing room 32. The air interstice 33 leading fuel vapor from the containing room 32 to the filling room 31 is disposed between the outer walls of the ventilating cap 4 and inter wall of the containing room 32.

Preferred: A plurality of protrusion 321 are disposed around the inter wall the containing room 32, the contacting surface of the bottom of the ventilating cap 4 and the containing room 32, to prevent the tight connection of the bottom of the ventilating cap 4 and the inter wall of the containing room 32. Through the gap composed by the a plurality of protrusion 321 and the bottom of the ventilating cap 4, the fuel vapor enters the air interstice 33. As of FIG. 3 shows that to achieve same technical effect, a plurality of gap also can be disposed on bottom of the ventilating cap 4, thus simplifying the complexity of the containing room 32, and reducing production cost.

The fuel-absorption substrate 5 is disposed in the filling room 31. The fuel vapor is filtered by the fuel-absorption substrate 5 in the filling room 31, then discharged to the atmosphere, to achieve the goal of controlling emission, and reducing pollution. Preferred: the fuel-absorption substrate 5 is activated charcoal.

The air outlet11 is disposed on the bottom of the containing room 32. The air outlet11 leads the vapored fuel to the containing room 32, and ensures that the residuary fuel in the containing room 32 is drained completely and quickly into the fuel tank under the negative pressure of the fuel tank, for better absorption function of the activated charcoal, and less environmental pollution.

Preferred: the bottom of the containing room 32 is funnel-shaped, ensuring that the residuary fuel in the containing room 32 is drained completely and quickly into the fuel tank under the negative pressure of the fuel tank, for better absorption function of the activated charcoal, and less environmental pollution.

The first breathing board 6, with the fuel-absorption substrate 5 above, covering the air interstice 33 between the ventilating cap 4 and inter wall of the containing room 32, is disposed above the bottom of the filling room 31. In this embodiment the inter wall of the filling room 31 is cylindrical shaped, and the diameter of the ventilating cap 4 is less than that of the filling room 31, thus the first breathing board 6 is disposed easily. The first breathing board 6 of two-layer non-woven cloth functions to double filter the fuel vapor entering the filling room 31 from the containing room 32, and prevent the entering of charcoal powder in the filling room 31 to the fuel tank to block carburetor.

The embodiment also includes the second breathing board 9, covering the fuel-absorption substrate 5, which is preferred as two-layer non-woven cloth and disposed near the top of the filling room 31, to prevent the leakage of the fuel-absorption substrate 5.

Preferably: the protrusion or reinforce rib is disposed on the bottom of the fuel tank outer cap 2 to push the second breathing board 9 downwards.

The slot 12 with the O-ring 8 inside, is disposed on the bottom of the fuel tank inner cap 1, to connect with the fuel tank, thus reducing environmental pollution caused by the liquid fuel/fuel vapor non-filtered by the fuel-absorption substrate 5 in the filling room 3.

As of what shown in FIG. 4, preferably: the connecting screw thread 13 is disposed on the bottom of the fuel tank inner cap 1 to connect with the fuel tank.

The separating board 100, covering the upper opening of the hollow room 3, is disposed between the fuel tank outer cap 2 and second breathing board 9. The separating board 100 pushes the second breathing board 9 downwards to prevent the leakage of fuel-absorption substrate 5.

The embodiment also includes the hook 7, disposed under the fuel tank inner cap 1 and clamping connected with the bottom of the containing room 32. In this embodiment, the hook 7 is disposed on the bottom center of the containing room 32, and a plurality of air outlet11 are disposed around and above the hook 7.

Furthermore: the breathing foam 110 is disposed within the air outlet11. The supporting panel is disposed on the connecting point between hook 7 and containing room 32 to prevent the drop of the breathing foam 110. The entering of liquid fuel/fuel vapor to the filling room 3 through the air interstice 33 and first breathing board 6, be buffered by the breathing foam 110, is more smooth, and the residuary fuel in the containing room 32 is drained completely and quickly into the fuel tank under the negative pressure of the fuel tank, for better absorption function of the activated charcoal.

The little liquid fuel and fuel vapor arising from the fuel tank during working process, following the flow of liquid fuel/fuel vapor, through the air outlet11, containing room 32, the air interstice 33, and the first breathing board 6, enters the filling room 31, then get filtered by the fuel-absorption substrate 5, and discharged to the atmosphere through the second breathing board 9 and the small pore 101 on the separating board 100.

Little liquid fuel enters the containing room 32 during the working process to protect charcoal powder. At the meantime, when the gasoline engine stops, following the flow of liquid fuel/fuel vapor, the little residuary fuel in the containing room 32 is drained completely and quickly into the fuel tank under the negative pressure of the fuel tank, for better absorption function of the activated charcoal, and less environment pollution.

When positive pressure or negative pressure occur in the fuel tank, the experimental data about the flow of the liquid fuel entering into the containing room 32 and little liquid fuel drained from the containing room 32 to the fuel tank in every minute is as the following:

Positive/Negative Pressure Unit: Kpa, Flow Unit: L/Min Positive Pressure 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0 9.0 10.0 Flow 0 1.23 2.29 3.00 3.54 4.10 4.48 4.85 5.24 5.67 Negative −2.0 −2.5 −3.0 −3.5 −4.0 −4.5 −5.0 −5.5 −6.0 −6.5 Pressure Flow 1.78 2.13 2.47 2.63 2.86 3.04 3.24 3.38 3.55 3.74

The above-described preferred embodiment of the present invention is not intended to limit the present invention, any modification within the spirit and principles of the present invention, made by the equivalent replacement, improvement, etc., should be included in the protection of the present invention within the range. 

1. A vertical shaft fuel tank cap with charcoal canister, comprising: a fuel tank inner cap; a fuel tank outer cap, wherein a hollow room with an upper opening is disposed in a center of said fuel tank inner cap, said fuel tank outer cap covering said upper opening and being disposed above said fuel tank inner cap; a ventilating cap disposed in said hollow room and dividing said hollow room into a filling room and containing room, said filling room being disposed above said containing room, said containing room having an air outlet leading fuel vapor to said containing room on a bottom of said containing room; and an air interstice leading fuel vapor from said containing room to said filling room, being disposed between outer walls of said ventilating cap and an inner wall of said containing room, said filling room containing a fuel-absorption substrate.
 2. The vertical shaft fuel tank cap with charcoal canister, according to claim 1, further comprising: a first breathing board, with said fuel-absorption substrate above, covering said air interstice and being disposed above the bottom of said filling room.
 3. The vertical shaft fuel tank cap with charcoal canister, according to claim 1, further comprising: a second breathing board covering said fuel-absorption substrate and being disposed above said upper outlet of said filling room.
 4. The vertical shaft fuel tank with charcoal canister, according to claim 3, further comprising: a separating board, covering said upper opening of said hollow room and being disposed between said fuel tank outer cap and said second breathing board.
 5. The vertical shaft fuel tank with charcoal canister, according to claim 1, further comprising: a plurality of protrusions disposed around said inner wall of said containing room, a contacting surface of said bottom of said ventilating cap and said containing room.
 6. The vertical shaft fuel tank with charcoal canister, according to claim 1, further comprising: a plurality of gap, being disposed on the bottom of said ventilating cap.
 7. The vertical shaft fuel tank with charcoal canister, according to claim 1, wherein said bottom of said containing room is funnel-shaped.
 8. The vertical shaft fuel tank with charcoal canister, according to claim 1, further comprising: a slot with an O-ring inside said slot, and a screw thread disposed on the bottom of said fuel tank inner cap, connecting with the fuel tank.
 9. The vertical shaft fuel tank with charcoal canister, according to claim 1, further comprising: a hook, being disposed under said fuel tank inner cap.
 10. The vertical shaft fuel tank with charcoal canister, according to claim 9, further comprising: a breathing foam disposed within said air outlet, and a supporting panel disposed on a connecting point between said hook and the bottom of said containing room so as to prevent drop of said breathing foam. 